Precision vise

ABSTRACT

A vise with the precision to match the quality expected of a Wire Electrical Discharge Machine. With the quality of the vise you can locate parts with extreme repeatability from part to part enabling to produce parts with exact duplication. With the range of the opening you are able to hold a variety of sizes of parts and with the low compact profile you are less likely to run into interference with the machine while in the cutting operation. Due to the exposure of water in the cutting operation on the Wire Electrical Discharge Machine the vise is made from stainless steel and for wear resistance the stainless steel of a heat treatable grade.

BACKGROUND OF THE INVENTION

[0001] In a circumstance of extremely high accuracy requirements as are met by a Wire Electrical Discharge Machine, a very close focus must be taken in the design of the holding systems and clamping pressures used. With the affect of the clamping pressure causing the object being clamped to be moved away from the alignment surface, the moveable jaw is designed to apply an inward movement to the alignment surface as the vise jaw is recieving clamping pressure.

[0002] Also, the guide track the moveable jaw rides in, is contoured in a way that is directly holding the walls of the vise from moving in an outward direction that would change or distort the alignment surface. This distortion would affect the locating and repeatability of the clamping location,thus changing the location or size of the repeating parts being made.

[0003] To otherwise combat this condition, a qualified operator of a Wire Electrical Discharge Machine would have to go through a complete set-up on every part machined. This set-up cost would not be conductive to a productive environment.

[0004] Also, due to the circumstance of working with sometimes very restrictive areas or small work, the vise must be constructed in a way that is not bulky or interfering with machine travel.

DESCRIPTION OF PRIOR ART

[0005] In the design of U.S. Pat. No. 4,925,168 a stationary jaw constructed of a base with a section of the structure extending outward is being used, and from that outward section there are two legs of the stationary jaw leading out and downward and connecting to a thin wall. This structure may help hold the workpiece close to the alignment, but the spring structure of the legs could prevent true reliability for location and keeping the work piece square while applying clamping pressure. It is claimed that in clamping, the workpiece will be tilted slightly therefore, a levelling head was incorporated to correct the tilt of the workpiece. In testing, with the proper squareness of the stationary jaw, this problem will be eliminated.

[0006] Also in the U.S. Pat. No. 4,925,168 the channel that the moveable jaw travels in, is constructed of abutment surfaces at an incline that assist in holding the side walls from being forced out during clamping pressure that will affect the parallel and squareness of the alignment surface. This distortion will cause a problem with the accuracy requirements set upon the process. In design evaluation, the construction of a radiused contour that will directly hold and support the outer walls to prevent any outer flexing. Also, this contour will give more locating surface and radiused corners are a proven condition to combat cracking conditions that would be a concern in any thin construction. These vises are of a thin construction due to the need to always minimize on any interferences to the work area..

FEDERALLY SPONSORED OR FUNDED

[0007] There was no federal funding or federally sponsored research in connection with this patent research.

SUMMARY OF THE INVENTION

[0008] In our design we have improved the contact surfaces in the slide channel that will more directly hold and support the side walls during the clamping operation. As the clamping action is applied to the vise, it commonly causes a pushing force in an outward direction. This movement would interfere with the quality expected in a Wire Electrical Discharge Machine.

[0009] In the design of our moveable jaw, we have developed a sliding insert that will always stay in solid contact with the moveable jaw. This solid contact will prevent any twist or spring tilting action in clamping. With the angle the insert is set in the moveable jaw, the clamping pressure will cause the insert to draw down in the vise which will aid in drawing the work piece tight to the allignment surface of the vise.

[0010] With the improvements in the slide channel for the moveable jaw and the design of an insert in the moveable jaw, combined, offers a design of a precision clamping vise that will offer both quality and long service to the users.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings you will see the contour of the channel that the moveable jaw travels by means of the drive screw. This contour developed by the use of radiuses is a strong structure to be used in an area requiring strength in a confined space. The low profile construction applies well to the clearance restrictions an operator may be concerned with when setting up a Wire Electrical Discharge Machine.

[0012] In the clamping operation (as clamping on #38)as the moveable jaw moves into the work piece the insert in the moveable jaw will slide in a inward direction and aid in forcing the work piece into the alignment surface #39.

DETAILED DISCRIPTION OF THE DRAWINGS

[0013] The main body of the vise #1 is precision ground to assure parallel and squareness. The quality of the grind is essential to the proper function of the vise in assembly. To mount the vise to the adapters for mounting to the machine tool as in a Wire Electrical Discharge Machine, screw fasteners are threaded into the four tapped holes #28. In hole #29 a slip fit pin is used as the pivot point to align the vise on an adapter. A cam pin located in slot #30 is used to slide the vise as the vise is being indicated true in the initial set-up. The pressure on the cam pin to pivot the vise is a safe way to pivot the vise due to the fact that you do not want to use a hammer force on a precision tool as this.

[0014] The guide channel contour starting with #25 aids in support and slide of the moveable jaw #36 along the vise body. This movement is required to allow the vise to hold a large range of part sizes. The radius contours #20 and #23 contribute strength to the inner corners of the moveable jaw as they contribute to stable locating surface. The radius contours of #21 and #24 are critical radius contours to help support and lock the side walls during clamping activity to prevent any outward flex of the side walls. These radius contours also contribute to added strength and prevention to cracking under pressure. The final focus on adding strength to the slide channel are added radius contours in area #26 and #27. These radius contours give strength and additional thickness to the side walls as they meet the vise body.

[0015] The screw #37 acts as the mechanical link that will drive the moveable jaw along the alignment surface to draw the jaw to the work piece. The surface #39 is the alignment surface that the work piece #38 is drawn to in the clamping pressure by the insert #34. As the screw is rotated in the contoured slide channel of the moveable jaw #36 the jaw will slide toward the face of the stationary jaw #35. The stationary jaw #35 is precision ground in relation to the alignment edge #39. This ground surface #35 assures that in clamping the work piece #38 is forced against surface #35 and this forced contact will assure the work piece #38 is against allignment surface #39 and is perfectly square to the axis of the Wire Electrical Discharge Machine.

[0016] The moveable jaw #36 as it travels along the contoured channel #25,#20,#21,#26,#27, #24,#23 will slide against the work piece #38. As the pressure is applied to the work piece#38, insert #34 resting against #36 the moveable jaw,insert #34 will slide inward toward the allignment surface #39. When relieved from pressure insert #34 will return to a neutral position driven by the elastic insert #31 until equal pressure is applied to the elastic insert #32. Elastic inserts #31 and #32 also support and lock insert #34 into the moveable jaw #36. 

The claims are as follows,
 1. A vise used in holding a work piece with very precise accuracy. The body of the vise is built in a way that the main surface represents the main alignment surface. This alignment surface will receive contact from the workpiece in its full length and give it the first axis of location and the main repeatability surface. A solid stationary jaw extending out of the body or main alignment surface will receive contact in the clamping operation. In the clamping, the stationary jaw identifies the second axis of location and repeatability. The body of the vise is constructed with a slot that runs the length of the vise to guide and carry the moveable jaw. The channel the moveable jaw travels through is constructed of radiused contours that will give direct support in preventing the side walls to be forced or flexed in an outward direction during the clamping operation. These radiused contours create a stronger guide will be less acustom to cracking.
 2. A vise jaw to assist in the holding the workpiece. The moveable jaw must assist in drawing the work piece to the alignment surface. In the moveable jaw, constructed of a second piece or insert, located on an abutted surface set at an angle. The angle is created in a way so as to cause movement when the pressure of the clamping action applied to the work piece it will cause an inward movement toward the alignment surface. To return the insert to a neutral position ready to perform the clamping and drawing function, it is held in place with elastic retainers. These elastic retainers give spring to the movement of the insert. The moveable jaw also has the same radiused contour on it that is in the vise body. Again, this radiused contour with a precision slip fit gives a more direct hold in preventing the side walls of the body from flexing outward in clamping pressure. This matched radiused contour will also create a stable slide surface for the moveable jaw. As in the body or in any structure, the matched radiused contour of the moveable jaw is less likely to ever crack.
 3. With the construction of the stationary jaw to be of solid material all part of the body structure and not an attachment to the body, this will assure solid non-movement. This solid constuction will assure relocating consistancy from work piece to work piece. This solid structure will also assure that the precision manufacturing, parallel and squareness will be maintaned and not move or change. This focus of repeatability is part of the value of using this type of tooling in a quality manufacturing process. 